Low-k damage avoidance during bevel etch processing

ABSTRACT

A method for etching a bevel edge of a substrate is provided. A patterned photoresist mask is formed over the etch layer. The bevel edge is cleaned comprising providing a cleaning gas comprising at least one of a CO 2 , CO, C x H y , H 2 , NH 3 , C x H y F z  and a combination thereof, forming a cleaning plasma from the cleaning gas, and exposing the bevel edge to the cleaning plasma. Features are etched into the etch layer through the photoresist features and the photoresist mask is removed.

This application is a Divisional of co-pending U.S. patent applicationSer. No. 11/510,309, filed Aug. 25, 2006, which is incorporated hereinby reference.

FIELD OF INVENTION

The present invention relates to the formation of semiconductor devices.More particularly, the present invention relates to the removal of etchbyproducts from a bevel edge during the formation of semiconductordevices. Even more particularly, the present invention relates to theavoidance of low-k damage in the removal of etch byproducts from a beveledge during the formation of semiconductor devices.

BACKGROUND OF THE INVENTION

In the processing of a substrate, e.g., a semiconductor substrate or aglass panel such as one used in flat panel display manufacturing, plasmais often employed. During substrate processing, the substrate is dividedinto a plurality of dies, or rectangular areas. Each of the plurality ofdies will become an integrated circuit. The substrate is then processedin a series of steps in which materials are selectively removed (oretched) and deposited. Control of the transistor gate critical dimension(CD) on the order of a few nanometers is a top priority, as eachnanometer deviation from the target gate length may translate directlyinto the operational speed and/or operability of these devices.

Typically, a substrate is coated with a thin film of hardened emulsion(such as a photoresist mask) prior to etching. Areas of the hardenedemulsion are then selectively removed, causing parts of the underlyinglayer to become exposed. The substrate is then placed on a substratesupport structure in a plasma processing chamber. An appropriate set ofplasma gases is then introduced into the chamber and a plasma isgenerated to etch exposed areas of the substrate.

During an etch process, etch byproducts, for example polymers composedof Carbon (C), Oxygen (O), Nitrogen (N), Fluorine (F), etc., are oftenformed on the top and the bottom surfaces near a substrate edge (orbevel edge). Etch plasma density is normally lower near the edge of thesubstrate, which results in accumulation of polymer byproducts on thetop and on the bottom surfaces of the substrate bevel edge. Typically,there are no dies present near the edge of the substrate, for examplebetween about 5 mm to about 15 mm from the substrate edge. However, assuccessive byproduct polymer layers are deposited on the top and bottomsurfaces of the bevel edge as a result of several different etchprocesses, organic bonds that are normally strong and adhesive willeventually weaken during subsequent processing steps. The polymer layersformed near the top and bottom surfaces of a substrate edge would thenpeel or flake off, often onto another substrate during post treatment,such as wet cleaning of the substrate surface, potentially affectingdevice yield.

Ultrafine feature sizes and high performance requirements havenecessitated the integration of low-k dielectrics on semiconductorwafers that are mechanically weaker than previous generation materials.The inherently weaker nature of the low-k dielectric material can posesignificant challenges to downstream electronic-packaging processes andmaterials.

Low-k materials are, by definition, those semiconductor-grade insulatingmaterials that have a dielectric constant (“k”) lower than 2.9. In orderto further reduce the size of devices on integrated circuits, it hasbecome necessary to use conductive materials having low resistivity andinsulators having low-k to reduce the capacitive coupling betweenadjacent metal lines. Low-k dielectric, carbon, or fluorine-doped filmsare being integrated into back-end-of-line (BEOL) stacks to improvedevice performance and allow for device scaling.

However, low-k materials are porous, which introduces a host of processintegration and materials compatibility difficulties. The balancing actbetween maintaining the film's integrity and integrating it properly andperforming the necessary stripping, cleaning, and conditioning getsincreasingly precarious. Patterning processes (etching, stripping, andcleaning) can also have a drastic impact on the integrity of the porouslow-k. Current cleaning plasma gases used are O₂ and CF₄ or N₂ and CF₄,which results in the migration of nitrogen, oxygen, or fluorine radicalsinto the substrate. The migration causes the k value to increase, whichchanges the composition and degrades the materials.

Thus, low-k damage results in degraded device performance, reducedreliability, lost yield, and other related problems.

SUMMARY OF THE INVENTION

To achieve the foregoing and in accordance with the purpose of thepresent invention a method for etching a bevel edge of a substrate isprovided. A patterned photoresist mask is formed over an etch layer. Thebevel edge is cleaned comprising providing a cleaning gas comprising atleast one of a CO₂, CO, C_(x)H_(y), H₂, NH₃, C_(x)H_(y)F_(z) or acombination thereof, forming a cleaning plasma from the cleaning gas,and exposing the bevel edge to the cleaning plasma. Features are etchedinto the etch layer through the photoresist features and the photoresistmask is removed.

Another manifestation of the invention provides for forming a patternedphotoresist mask over an etch layer. Features are etched into the etchlayer through the photoresist features and the photoresist mask isremoved. The bevel edge is cleaned comprising providing a cleaning gascomprising at least one of a CO₂, CO, C_(x)H_(y), H₂, NH₃,C_(x)H_(y)F_(z) or a combination thereof, forming a cleaning plasma fromthe cleaning gas, and exposing the bevel edge to the cleaning plasma.

In another manifestation of the invention, an apparatus for etching abevel edge of a substrate is provided. A plasma processing chamber,comprising a chamber wall forming a plasma processing chamber enclosure,a substrate support for supporting a substrate within the plasmaprocessing chamber enclosure, wherein the substrate support has adiameter smaller than a diameter of the substrate, a pressure regulatorfor regulating the pressure in the plasma processing chamber enclosure,at least one electrode for providing power to the plasma processingchamber enclosure for sustaining a plasma, a gas inlet for providing gasinto the plasma processing chamber enclosure, and a gas outlet forexhausting gas from the plasma processing chamber enclosure is provided.A gas source is in fluid connection with the gas inlet, where the gassource comprises a cleaning gas source, a cleaning plasma gas source,and an etch layer etch gas source. A controller is controllablyconnected to the gas source and the at least one electrode. Thecontroller comprises at least one processor and computer readable media.The computer readable media comprises computer readable code for forminga patterned photoresist mask over an etch layer, computer readable codefor cleaning the bevel edge comprising computer readable code forproviding a cleaning gas comprising at least one of a CO₂, CO,C_(x)H_(y), H₂, NH₃, C_(x)H_(y)F_(z) or a combination thereof, computerreadable code for forming a cleaning plasma from the cleaning gas, andcomputer readable code for exposing the bevel edge to the cleaningplasma. The computer readable media further comprises computer readablecode for etching features into the etch layer through the photoresistfeatures and computer readable code for removing the photoresist mask.

These and other features of the present invention will be described inmore detail below in the detailed description of the invention and inconjunction with the following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 is a high level flow chart of a process that may be used in anembodiment of the invention.

FIG. 2 is a high level flow chart of a process that may be used inanother embodiment of the invention.

FIGS. 3A-C are schematic cross-sectional and top views of a stackprocessed according to an embodiment of the invention.

FIG. 4 is a more detailed flow chart of a step of cleaning the beveledge.

FIGS. 5A and 5B are schematic views of a bevel etch processing chamberthat may be used in practicing the invention.

FIGS. 6A and 6B is a schematic view of an embodiment of a plasmaprocessing chamber that may be used in practicing the invention.

FIGS. 7A-B illustrate a computer system, which is suitable forimplementing a controller used in embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described in detail with reference toa few preferred embodiments thereof as illustrated in the accompanyingdrawings. In the following description, numerous specific details areset forth in order to provide a thorough understanding of the presentinvention. It will be apparent, however, to one skilled in the art, thatthe present invention may be practiced without some or all of thesespecific details. In other instances, well known process steps and/orstructures have not been described in detail in order to notunnecessarily obscure the present invention.

To facilitate understanding, FIG. 1 is a high level flow chart of aprocess that may be used in an embodiment of the invention. Withreference to FIG. 1, a patterned photoresist mask is provided (step100). FIG. 3A is a schematic cross-sectional view of a layer to beetched 308 over a substrate 304, with a patterned photoresist mask 312with photoresist features 314, over an underlayer 310, over the layer308 to be etched forming a stack 300. The photoresist mask has aphotoresist feature critical dimension (CD), which may be the widestpart of the width of the smallest possible feature. To provide thepatterned photoresist mask, a photoresist layer may be first formed overthe layer to be etched. Then the photoresist layer is patterned to formphotoresist features 314.

Optionally, the substrate may be transferred to a bevel etch chamber(step 102). As described in detail below, one plasma chamber may be usedto perform all the steps for forming the semiconductor. However, in analternative embodiment, a separate chamber may be used to clean thebevel edge. Thus, the substrate must be transferred to the bevel etchchamber to clean the bevel edge.

The bevel edge may be cleaned (step 104). FIG. 4 is a more detailed flowchart of this step. As shown in FIG. 4, cleaning the bevel edgecomprises the steps of providing a cleaning gas (step 404), forming acleaning plasma (step 406), and exposing the bevel edge to the cleaningplasma (step 408). The cleaning gas may be CO₂, CO, C_(x)H_(y), H₂, NH₃,C_(x)H_(y)F_(z) or a combination thereof. Cleaning gas having a chemicalformula C_(x)H_(y) may be CH₄, C₂H₆, and C₂H₄Cleaning gas having achemical formula C_(x)H_(y)F_(z) may be CH₃F, CHF₃, CH₂F₂, or C₂H₂F₄.The cleaning plasma may comprise CO₂, CO, C_(x)H_(y), H₂, NH₃,C_(x)H_(y)F_(z) or a combination thereof.

Not intended to be bound by any limitations or theories, it is believedthat CO or CO₂ works best followed by C_(x)H_(y), H₂, C_(x)H_(y)F_(z),and NH₃. Additionally, it is believed that CO₂ and CF₄ reduces theamount of oxygen and fluorine radicals. Thus, the use of CO or CO₂ ismost preferred. Use of C_(x)H_(y) is next most preferred. Use H₂ is nextmost preferred. Use of C_(x)H_(y)F_(z) is next preferred, and use of NH₃is the next preferred.

Optionally, the substrate may be transferred back to a plasma etchchamber (step 106). As described in detail below, one plasma chamber maybe used to perform all the steps for forming the semiconductor. However,in an alternative embodiment, a separate chamber may be used to etch thefeatures in the etch layer. Thus, the substrate must be transferred tothe plasma etch chamber to etch the features.

Features 328 are then etched into the etch layer 308 through thephotoresist mask 312 (step 108), as shown in FIG. 3B. The photoresistmask 312 is then removed (step 110), as shown in FIG. 3C.

Optionally, the substrate may be transferred back a bevel etch chamber(step 112). The bevel edge may be cleaned again (step 114) as describedabove with reference to FIG. 4.

FIG. 2 is a high level flow chart of a process that may be used inanother embodiment of the invention. A patterned photoresist mask isprovided (step 200) as stated above with reference to FIG. 3A. Features328 are then etched into the etch layer 308 through the photoresist mask312 (step 202), as shown in FIG. 3B. The photoresist mask 312 is thenremoved (step 204), as shown in FIG. 3C.

Optionally, the substrate may be transferred to a bevel etch chamber(step 206). As described in detail below, one plasma chamber may be usedto perform all the steps for forming the semiconductor. However, in analternative embodiment, a separate chamber may be used to clean thebevel edge. Thus, the substrate must be transferred to the bevel etchchamber to clean the bevel edge.

The bevel edge may be cleaned (step 208). As shown in FIG. 4, cleaningthe bevel edge comprises the steps of providing a cleaning gas (step404), forming a cleaning plasma (step 406), and exposing the bevel edgeto the cleaning plasma (step 408). The cleaning gas may be CO₂, CO,C_(x)H_(y), H₂, NH₃, C_(x)H_(y)F_(z) or a combination thereof. Cleaninggas having a chemical formula C_(x)H_(y) may be CH₄, C₂H₆, andC₂H₄Cleaning gas having a chemical formula C_(x)H_(y)F_(z) may be CH₃F,CHF₃, CH₂F₂, or C₂H₂F₄. The cleaning plasma may comprise CO₂, CO,C_(x)H_(y), H₂, NH₃, C_(x)H_(y)F_(z) or a combination thereof.

Not intended to be bound by any limitations or theories, it is believedthat CO or CO₂ works best followed by C_(x)H_(y), H₂, C_(x)H_(y)F_(z),and NH₃. Additionally, it is believed that CO₂ and CF₄ reduces theamount of oxygen and fluorine radicals. Thus, the use of CO or CO₂ ismost preferred. Use of C_(x)H_(y) is next most preferred. Use H₂ is nextmost preferred. Use of C_(x)H_(y)F_(z) is next preferred, and use of NH₃is the next preferred.

The underlayer 310 may be any known organic, inorganic, or metal layer.For exemplary purposes and not intended to be limiting, the underlayermay be an anti-reflective layer (ARL), bottom anti-reflective coating(BARC), dielectric anti-reflective coating (DARC), amorphorous carbon,or any other known underlayers.

Example

In an example of this process, a patterned photoresist layer is formed(step 100, 200). A substrate 304, with the etch layer 308, an underlayer310, a patterned photoresist mask 312, and a bevel edge 316 is placed ina plasma processing chamber.

FIGS. 5A and 5B illustrate an embodiment of a bevel etch process chamber500 enclosed by chamber walls 502. Chamber 500 has a substrate support540 with a substrate 550 on top. In one embodiment, the substratesupport 540 is an electrostatic chuck, which is powered by a RF (radiofrequency) power source (not shown). The substrate support 540 can be DC(direct current), RF biased, or grounded. The substrate support 540 mayhave a diameter less than a diameter of the substrate 550 to allow forcleaning of the bevel edge. Opposing the substrate support 540 is a gasdistribution plate 560 with a gas inlet 561. During etching of substrate550, chamber 500 can be RF powered to generate capacitively coupled etchplasma or inductively coupled etch plasma.

The substrate 550 may have a bevel edge 517 that includes a top and abottom surface of the edge of the substrate, as shown in region B ofFIG. 5A and enlarged region B in FIG. 5B. In FIG. 5B, bevel edge 517 ishighlighted as a bold solid line and curve.

Surrounding the edge of substrate support 540, there is a bottom edgeelectrode 520, made of conductive materials, such as aluminum (Al).Between the substrate support 540 and the bottom edge electrode 520,there is a bottom dielectric ring 521 electrically separating thesubstrate support 540 and the bottom edge electrode 520. In oneembodiment, substrate 550 is not in contact with the bottom edgeelectrode 520. Beyond the bottom edge electrode 520, there is anotherbottom insulating ring 525, which extends the surface of the bottom edgeelectrode 520 facing substrate 550.

Surrounding the gas distribution plate 560, there is a top edgeelectrode 510, made of conductive materials, such as aluminum (Al). Thetop edge electrode 510 is electrically insulated from the gasdistribution plate 560 by a top dielectric ring 511. Beyond the top edgeelectrode 510, there is top insulating ring 515, which extends thesurface of the top edge electrode 510 facing substrate 550.

In one embodiment, the bottom edge electrode 520 is coupled to a RFpower source 525 and the top edge electrode 510 is grounded. During asubstrate bevel edge cleaning process, the RF power source 525 suppliesRF power at a frequency between about 2 MHz to about 15 MHz and a powerbetween about 100 watts to about 2000 watts to generate a cleaningplasma. During bevel edge cleaning the substrate support 540 and the gasdistribution plate 560 are kept electrically floating. The cleaningplasma is configured to be confined by the top dielectric ring 511, topedge electrode 510, the top insulating ring 515, the bottom dielectricring 521, the bottom edge electrode 520, and the bottom insulating ring.

The bevel etch chamber pressure may be between about 100 mTorr to about2 Ton during the bevel edge cleaning process. The spacing between thegas distribution plate 560 and substrate 550, D_(S), is less than 0.6 mmto ensure no plasma is formed between the top electrode 560 and thesubstrate 550 during the bevel edge cleaning process. The cleaninggas(es) may be supplied from any gas source (not shown) that is in fluidconnection with gas inlet 561 and is exhausted from the chamber througha gas outlet by the exhaust pump 550. In one embodiment, the gas inletis located near the center of the gas distribution plate 560.Alternatively, the cleaning gas(es) can also be supplied through gasinlet(s) disposed in other parts of the process chamber 500. Acontroller 504 is controllably connected to the RF sources 525, the gassource, and any other devices.

Other embodiments of the chamber are illustrated in U.S. patentapplication Ser. No. 11/440,561 filed May 24, 2006, entitled “Apparatusand Methods To Remove Films On Bevel Edge and Backside of Wafer”, whichis incorporated herein in its entirety for all purposes.

FIGS. 6A and 6B is a schematic view of an embodiment of a plasmaprocessing chamber that may be used in practicing the invention. Theplasma processing chamber 600 may clean and etch the substrate such thatthe substrate would not have to be transferred between chambers, therebyreducing process time, contamination, and other related issues. Sincethe plasma processing chamber 600 is similar to the chamber discussedwith reference to FIG. 5, only the relevant elements will be discussed.

The processing chamber 600 may have a top electrode 602 and a bottomelectrode 604. To facilitate the bevel etch, the diameter of thesubstrate 610 is greater than the diameter of the bottom electrode 604which supports the substrate. The cleaning gas(es) may be supplied fromany gas source that is in fluid connection with a gas inlet (illustratedin FIG. 5A). The cleaning gas(es) may be used to form cleaning plasma608 between electrodes 602, 604. To clean the substrate, the electrodes602, 604 may be moved toward each other thereby forcing the cleaningplasma 608 to the sides of the chamber 600 as illustrated in FIG. 6B.Therefore, the electrodes 602, 604 are closer together during the beveletch than during the etch layer etch. Namely, the top electrode 602 andthe bottom electrode 604 are separated during the etching process of theetch layer and are closer together during the etching process of thebevel edge. The bevel edges are cleaned by being exposed to the cleaningplasma 608.

FIGS. 7A and 7B illustrate a computer system 700, which is suitable forimplementing a controller 504 used in embodiments of the presentinvention. FIG. 7A shows one possible physical form of the computersystem. Of course, the computer system may have many physical formsranging from an integrated circuit, a printed circuit board, and a smallhandheld device up to a huge super computer. Computer system 700includes a monitor 702, a display 704, a housing 706, a disk drive 708,a keyboard 710, and a mouse 712. Disk 714 is a computer-readable mediumused to transfer data to and from computer system 700.

FIG. 7B is an example of a block diagram for computer system 700.Attached to system bus 720 is a wide variety of subsystems. Processor(s)722 (also referred to as central processing units, or CPUs) are coupledto storage devices, including memory 724. Memory 724 includes randomaccess memory (RAM) and read-only memory (ROM). As is well known in theart, ROM acts to transfer data and instructions uni-directionally to theCPU and RAM is used typically to transfer data and instructions in abi-directional manner. Both of these types of memories may include anysuitable of the computer-readable media described below. A fixed disk726 is also coupled bi-directionally to CPU 722; it provides additionaldata storage capacity and may also include any of the computer-readablemedia described below. Fixed disk 726 may be used to store programs,data, and the like and is typically a secondary storage medium (such asa hard disk) that is slower than primary storage. It will be appreciatedthat the information retained within fixed disk 726 may, in appropriatecases, be incorporated in standard fashion as virtual memory in memory724. Removable disk 714 may take the form of any of thecomputer-readable media described below.

CPU 722 is also coupled to a variety of input/output devices, such asdisplay 704, keyboard 710, mouse 712, and speakers 730. In general, aninput/output device may be any of: video displays, track balls, mice,keyboards, microphones, touch-sensitive displays, transducer cardreaders, magnetic or paper tape readers, tablets, styluses, voice orhandwriting recognizers, biometrics readers, or other computers. CPU 722optionally may be coupled to another computer or telecommunicationsnetwork using network interface 740. With such a network interface, itis contemplated that the CPU might receive information from the network,or might output information to the network in the course of performingthe above-described method steps. Furthermore, method embodiments of thepresent invention may execute solely upon CPU 722 or may execute over anetwork such as the Internet in conjunction with a remote CPU thatshares a portion of the processing.

In addition, embodiments of the present invention further relate tocomputer storage products with a computer-readable medium that havecomputer code thereon for performing various computer-implementedoperations. The media and computer code may be those specially designedand constructed for the purposes of the present invention, or they maybe of the kind well known and available to those having skill in thecomputer software arts. Examples of computer-readable media include, butare not limited to: magnetic media such as hard disks, floppy disks, andmagnetic tape; optical media such as CD-ROMs and holographic devices;magneto-optical media such as floptical disks; and hardware devices thatare specially configured to store and execute program code, such asapplication-specific integrated circuits (ASICs), programmable logicdevices (PLDs) and ROM and RAM devices. Examples of computer codeinclude machine code, such as produced by a compiler, and filescontaining higher level code that are executed by a computer using aninterpreter. Computer readable media may also be computer codetransmitted by a computer data signal embodied in a carrier wave andrepresenting a sequence of instructions that are executable by aprocessor.

The bevel edge may be cleaned (step 104). With reference to the stepsshown in FIG. 4, an example recipe of providing a cleaning gas (step404) would use, for example, a gas of at least one of CO₂, CO,C_(x)H_(y), H₂, NH₃, C_(x)H_(y)F_(z) or a combination thereof from whicha cleaning plasma may be formed (step 406). A plasma processing chambermay have a pressure of 500 mTorr-2 Ton. More preferably, the pressurefor cleaning the bevel edge is between 100 mT-2 T. 100 to 2000 Watts ofpower are supplied to the plasma processing chamber at about 2-27 MHz.In one embodiment of a recipe, 5-1000 sccm of cleaning gas may be usedat a temperature of 40° C. for longer than 5 seconds.

Features are then etched into the etch layer (step 108). An example of alayer to be etched is may be a conventional etch layer, such as SiN,SiC, an oxide, or low-k dielectric. A conventional etch recipe may beused to etch the layer to be etched.

To remove the mask (step 110) an oxygen ashing may be used.

In a preferred embodiment of the invention, the cleaning of the beveledge and etching the features into the etch layer are done in situ inthe same etch chamber, as illustrated in FIGS. 6A and 6B.

In another embodiment, features are etched into the etch layer (step202). An example of a layer to be etched is may be a conventional etchlayer, such as SiN, SiC, an oxide, or low-k dielectric. A conventionaletch recipe may be used to etch the layer to be etched.

To remove the mask (step 204) an oxygen ashing may be used.

The bevel edge may be cleaned (step 208). With reference to the flowchart shown in FIG. 4, an example recipe of providing a cleaning gas(step 404) would use, for example, a gas of at least one of CO₂, CO,C_(x)H_(y), H₂, NH₃, C_(x)H_(y)F_(z) or a combination thereof from whicha cleaning plasma may be formed (step 406). An etch chamber or plasmaprocessing chamber may have a pressure of 500 mTorr-2 Torr. Morepreferably, the pressure for cleaning the bevel edge is between 100 mT-2T. 100 to 2000 Watts of power are supplied to the plasma processingchamber at about 2-27 MHz. In one embodiment of a recipe, 5-1000 sccm ofcleaning gas may be used at a temperature of 40° C. for longer than 5seconds.

While this invention has been described in terms of several preferredembodiments, there are alterations, permutations, and various substituteequivalents, which fall within the scope of this invention. It shouldalso be noted that there are many alternative ways of implementing themethods and apparatuses of the present invention. It is thereforeintended that the following appended claims be interpreted as includingall such alterations, permutations, and various substitute equivalentsas fall within the true spirit and scope of the present invention.

1. An apparatus for etching a bevel edge of a substrate, comprising: aplasma processing chamber, comprising: a chamber wall forming a plasmaprocessing chamber enclosure; a substrate support for supporting asubstrate within the plasma processing chamber enclosure, wherein thesubstrate support has a diameter smaller than a diameter of thesubstrate; a pressure regulator for regulating the pressure in theplasma processing chamber enclosure; at least one electrode forproviding power to the plasma processing chamber enclosure forsustaining a plasma; a gas inlet for providing gas into the plasmaprocessing chamber enclosure; and a gas outlet for exhausting gas fromthe plasma processing chamber enclosure; a gas source in fluidconnection with the gas inlet, comprising: a cleaning gas source; and anetch layer etch gas source; and a controller controllably connected tothe gas source and the at least one electrode, comprising: at least oneprocessor; and computer readable media comprising: computer readablecode for forming a patterned photoresist mask over an etch layer;computer readable code for etching features into the etch layer throughthe photoresist features; computer readable code for removing thephotoresist mask; computer readable code for cleaning the bevel edgeafter said removing the photoresist mask, comprising: computer readablecode for providing a cleaning gas comprising at least one of a CO₂ orCO; computer readable code for forming a cleaning plasma from thecleaning gas; and computer readable code for exposing the bevel edge tothe cleaning plasma, the bevel edge exposed to the cleaning plasmaincluding at least an edge portion of a top surface at an edge of thesubstrate.
 2. The apparatus of claim 1, wherein the plasma processingchamber further comprises: a gas distribution plate, the controllerbeing further controllably connected to the gas distribution plate. 3.The apparatus of claim 2, wherein the computer readable code for etchingfeatures comprises: computer readable code for moving the gasdistribution plate to a distance greater than 0.6 mm from the topsurface of the substrate, and wherein the computer readable code forcleaning the bevel edge further comprises: computer readable code formoving the gas distribution plate to a distance less than 0.6 mm fromthe top surface of the substrate.
 4. The apparatus of claim 2, whereinthe computer readable code for forming the cleaning plasma comprises:computer readable code for placing the gas distribution plate at a closedistance from a top surface of the substrate such that the cleaningplasma is not formed between the gas distribution plate and thesubstrate during the bevel edge cleaning.
 5. The apparatus of claim 2,wherein the computer readable code for cleaning the bevel edge furthercomprises: computer readable code for keeping the substrate support andthe gas distribution plate electrically floating during the bevel edgecleaning.
 6. The apparatus of claim 2, wherein the at least oneelectrode comprises: a top edge electrode and a bottom edge electrode,the top edge electrode surrounding an edge of the gas distribution plateand the bottom edge electrode surrounding an edge of the substratesupport, wherein the computer readable code for forming the cleaningplasma comprises: computer readable code for forming the cleaning plasmabetween the top edge electrode and the bottom edge electrode.
 7. Theapparatus of claim 2, wherein the computer readable code for exposingthe bevel edge comprises: computer readable code for flowing thecleaning plasma only from the gas distribution plate over the topsurface of the substrate.
 8. The apparatus of claim 1, wherein the atleast one electrode comprises a top electrode and a bottom electrode,and wherein the computer readable code for exposing the bevel edge tothe cleaning plasma comprises: computer readable code for moving atleast one of the top electrode and the bottom electrode toward the otherso as to force the cleaning plasma to sides of the plasma processingchamber.
 9. The apparatus of claim 1, wherein the bevel edge exposed tothe cleaning plasma further includes an edge portion of a bottom surfaceat the edge of the substrate.
 10. The apparatus of claim 1, wherein thecleaning gas further comprises hydrocarbons.
 11. The apparatus of claim1, wherein the cleaning gas further comprises H₂.
 12. An apparatus foretching a bevel edge of a substrate, comprising: a bevel etch chamber,comprising: a chamber wall forming a bevel etch chamber enclosure; asubstrate support for supporting a substrate within the bevel etchchamber enclosure, wherein the substrate support has a diameter smallerthan a diameter of the substrate; a pressure regulator for regulatingthe pressure in the bevel etch chamber enclosure; at least one electrodefor providing power to the bevel etch chamber enclosure for sustaining aplasma; a gas distribution plate; a gas inlet for providing gas into theplasma processing chamber enclosure; and a gas outlet for exhausting gasfrom the bevel etch chamber enclosure; a gas source in fluid connectionwith the gas inlet, comprising a cleaning gas comprising at least one ofa CO₂ or CO; and a controller controllably connected to the gas source,the gas distribution plate, and the at least one electrode, comprising:at least one processor; and computer readable media comprising: computerreadable code for providing a cleaning gas comprising at least one of aCO₂ or CO; computer readable code for forming a cleaning plasma from thecleaning gas; and computer readable code for cleaning the bevel edgewith the cleaning plasma, including computer readable code for placingthe gas distribution plate at a close distance from a top surface of thesubstrate such that the cleaning plasma is not formed between the gasdistribution plate and the substrate during the bevel edge cleaning, thebevel edge exposed to the cleaning plasma including at least an edgeportion of a top surface at an edge of the substrate.
 13. The apparatusof claim 12, wherein the computer readable code for cleaning the beveledge further comprises: computer readable code for flowing the cleaningplasma only from the gas distribution plate over the top surface of thesubstrate.
 14. The apparatus of claim 12, wherein the at least oneelectrode comprises a top electrode and a bottom electrode, and whereinthe computer readable code for cleaning the bevel edge furthercomprises: computer readable code for moving at least one of the topelectrode and the bottom electrode toward the other, forcing thecleaning plasma to sides of the plasma processing chamber so as toexpose the bevel edge to the cleaning plasma.
 15. The apparatus of claim12, wherein the bevel edge exposed to the cleaning plasma furtherincludes an edge portion of a bottom surface at the edge of thesubstrate.
 16. The apparatus of claim 12, wherein the computer readablecode for cleaning the bevel edge further comprises: computer readablecode for keeping the substrate support and the gas distribution plateelectrically floating during the bevel edge cleaning.
 17. The apparatusof claim 12, wherein the at least one electrode comprises: a top edgeelectrode and a bottom edge electrode, the top edge electrodesurrounding an edge of the gas distribution plate and the bottom edgeelectrode surrounding an edge of the substrate support, and wherein thecomputer readable code for forming the cleaning plasma comprises:computer readable code for forming the cleaning plasma between the topedge electrode and the bottom edge electrode.
 18. The apparatus of claim12, wherein the cleaning gas further comprises hydrocarbons.
 19. Theapparatus of claim 12, wherein the cleaning gas further comprises H₂.